NWS Forecast Discussion
815
FXUS61 KCTP 101142
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
642 AM EST Wed Dec 10 2025
.SYNOPSIS...
*Breezy with wet snow of varying intensity over the Northern
Mountains of Pennsylvania with areas of snow changing to mixed
precip or rain across Central and Southern PA today into this
evening
*Snow showers and localized, narrow bands of snow squalls
continue late tonight through Thursday. Wind gusts of 35 to
45 mph from the West or Northwest on Thursday.
*Additional bouts of winter weather possible Friday-Sunday
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Widespread clouds and a light south to southwest sfc breeze with
fairly uniform temps between 25-30F were noted this morning
across the CWA. Leading edge of steady light snow at 09Z was
seen near the RT 219 corridor. Max wet bulb temps in the 950 to
900 mb layer range from 0-1C across Warren, Elk and McKean
Counties to -2 to -5C across the rest of the region with the
coldest air locked in across the Ncent Mtns of PA. A focused
area of deeper ascent beneath the coupled jets (right
entrance/left exit regions will occur over a slow moving warm
front (extending Southeastward from a 990 mb sfc low over
SW Lower Michigan at daybreak) and the steepest part of the LLVL
cold dome over Northern PA. This UVVEL will lead to snow of
varying intensity today to the North of Interstate 80, and
periods of lighter snow, that will become mixed with or change
to intermittent light rain this afternoon across the southern
half of the state.
Max wet bulb temps in the 950-900 mb layer dont get above zero
from the mid Susq Valley NE to the Endless Mtns and Poconos, so
the precip type there should stay mainly, or ALL snow today.
All snow for the bulk of this synoptic event with anywhere from
2-6 inches of wet snow across the Northern Mtns and 1-3 inches
over the Laurels.
Local max ~6" may be found in the higher terrain in Sullivan
County. Snow rates are projected to be in the 0.50-1 in/hr range
in the NW mtns during the 5-10AM window before shifting
eastward across north central PA toward the Poconos.
The main period of impact to travel by this winter weather
across the Central Mtns, Lower Susq Valley and Laurel Highlands will
be through 15Z today, followed by the precip type transition and
sfc temps warming into the mid/upper 30s and low 40s (south).
Temps are expected to rise above the freezing mark particularly
along and southeast of I99/I80 corridor by the afternoon. Temps
could stay a few degrees colder in the northern tier, but road
snow will likely become more limited after midday given the
marginal air/road temps.
Intermittent snow/rain in the valleys along I99/US220 corridor
from Blair/Centre County east along I80/US220 should result in a
slushy coating to 1 inch. There is a scenario where wetbulb
effects help to lock in colder air for a longer duration over
the central ridge/valley region, which may result in a bit more
snow than currently fcst.
No change in Winter Weather Advisories for this initial,
clipper event.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Precip tapers off this evening as the approx 990 mb sfc low
moves to near KART, and the bulk of the CWA falls within the
warm sector for up to several hours.
The lows southwestward trailing cold front pushes through the
state early tonight followed by a transition to windy and
notably colder conditions with long, narrow bands of LES snow
showers/squalls with a multi-lake upstream connection.
Extended Winter Weather Advisories for LES across our NW Mtns
through much of Thursday night, with another 2-5 inches likely
and localized amounts around 6 inches. This could bring 48 hour
snow totals to around 12 inches across parts of the NW Mtns near
and to the North of Rt 6 INVOF KBFD.
Winds increase late tonight through Thursday with frequent
gusts in the 30-35 mph range; locally higher gusts up to 40-45
mph are likely, esp across the Laurel Highlands. Given the wet
character of the snow early on Wednesday, blowing and drifting
impacts are not a concern at least initially. However, as temps
fall into tonight, expect the character of the snow to become
drier or more fluffy which increases the potential for blowing
and drifting over the higher terrain tonight. Wet surfaces and
slush areas will be prone to refreezing and icy spots overnight
tonight into early Thursday morning.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Pattern supports fast moving weaker systems, mainly to the
north and south. Wide swings in guidance at times, given the
large scale pattern.
For the next system, the highest chance for snow later Friday
is mainly south of our area again.
Pattern supports an abnormally cold period.
Earlier discussion below.
Lake effect snow showers and gusty northwesterly winds
continue on Thursday with additional snow accums expected over
the northwestern mountains and Laurel Highlands. A few long
fetch bands or locally heavy snow showers/squalls are possible
on Thursday and could extend as far southeast as I81.
Winter weather/periods of snow continue from Friday through the
weekend and into early next week with a series of upper troughs
and clippers followed by reinforced cold NW flow and lake
effect/upslope snow showers. Temperatures remain below the
historical average heading into mid-December.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Areas of snow associated with a clipper system continue to move
into central PA from the west. The main uncertainty in the
forecast arises from the precipitation type forecast. BFD should
see all snow, but all other TAF sites will have the potential
for mixed precip or even just plain rain. Any sites that see
snow will have the potential to see visibility drop to IFR.
Ceilings will lower to MVFR from west to east through the
morning and into the early afternoon.
LLWS will remain a concern into the afternoon as a 45 to 60
knot low-level jet traverses the region. Behind the cold front
Wed evening into Thu, winds will turn out of the west and
increase with sfc gusts 15-35 kts (highest for JST and AOO).
Precipitation ends for most of Central PA by 00Z Thursday as the
system exits to the east, but lake effect and upslope snow
showers continue for BFD and JST. Much of the region will see
conditions improve to VFR as precip comes to an end, but MVFR
conditions will persist at BFD and JST.
Outlook...
Thu...Snow showers continue, mainly N/W PA. Windy.
Fri-Sun...Additional rounds of light snow possible with multiple
clipper systems.
&&
.CLIMATE...
Bradford, PA had two records in one night! Their temp of -4F
just before midnight EST on 12/8 broke the previous record of -2F
set in 1970.
As the temp continued falling through the night, they tied the
12/9 record low of -12F at 618 AM EST. This tied the record set
in 2002.
Astronomical winter (solstice) begins at 10:03 a.m. on Sunday,
December 21st.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 4 AM EST Friday for PAZ004>006-
010-011-017.
Winter Weather Advisory until 10 PM EST this evening for
PAZ012-018-037-041-042.
Winter Weather Advisory from 10 AM this morning to 10 AM EST
Thursday for PAZ024-033.
&&
$$
SYNOPSIS...Lambert/Steinbugl
NEAR TERM...Lambert/Steinbugl
SHORT TERM...Lambert/Steinbugl
LONG TERM...Lambert/Steinbugl/Martin
AVIATION...Bauco
CLIMATE...Martin/Colbert
NWS CTP Office Area Forecast Discussion
